Airships were once the giants of the skies. They were soaring before the airplane and were used as the first strategic bombers in World War I. What happened? Blimp technology has come a long way since the Hindenburg. Ira Flatow and guests discuss airships of the past and future.

China burns as much coal as the rest of the world combined. But it also leads in clean tech, and has a national climate change policy in place. A look at how the world is tackling climate change--with or without us.

The Personal Genome Project is attempting to find 100,000 volunteers to publish their entire genetic makeup â€” including their physical traits â€” online. So far, ten individuals have chosen to share their DNA sequences, medical records, and other personal information with the research community and the general public.

It's easy to find a dictionary definition of "time." But ask a group of theoretical physicists and the answer isn't as clear. Sean Carroll of CalTech discusses the mysteries of time in his book, From Eternity to Here: The Quest for the Ultimate Theory of Time.